The invention is directed to a thermoplastic molding composition, which contains ABS and polycarbonate and to articles molded therefrom, and more particularly to metal plated articles molded therefrom.
A thermoplastic molding composition containing a major amount of polycarbonate and a lesser amount of butadiene based graft polymer is disclosed. The inventive composition is especially suited for the preparation of a molded article wherein at least some of its surface is metallized by an electroless plating process. The thus plated article is characterized in its improved heat resistance and excellent adhesion of its metal plating.
Thermoplastic molding composition containing polycarbonates and ABS polymers have been known for some time, see for example DE-A 1 170 141 which describes the favorable processing properties of such molding compositions. Also relevant are U.S. Pat. Nos. 3,130,177, 3,162,695 and 3,852,393 and British Patent No. 1,253,226.
Also known are thermoplastic molding compositions containing polycarbonate and acrylate based plating modifiers (U.S. Pat. No. 4,828,921) or ABS which are suitable for electroless metal plating. In general, the polycarbonate content in these compositions is kept low as it has long been recognized that the presence of polycarbonate in relatively high amounts is the cause of difficulties in electroless metal-plating (see U.S. Pat. Nos. 5,198,096 and 5,087,524). On the other hand, the heat resistance of the composition is directly related to the polycarbonate level. Blends containing a higher content of polycarbonate feature better thermal performance. The art has long sought a molding composition that would combine good heat resistance with good plating characteristics. The composition of the present invention addresses this goal. Special processes for electroless plating of polycarbonate have been described in U.S. Pat. Nos. 5,087,524 and 5,198,096.
Processes for electroless plating have been disclosed in U.S. Pat. No. 4,125,649 and in the Encyclopedia of Polymer Science and Technology, Vol. 8, both incorporated by reference herein.